Search found 308 matches

by Jim Kovalchick
Tue May 01, 2018 3:29 pm
Forum: Images du Jour
Topic: MATER-1
Replies: 10
Views: 1541

Re: MATER-1

Roberto, Their stem has a relatively thick alumina tube insulating it between the insulator and the stainless grid connector. Originally they put a thin alumina tube on a stem piece after the connector and before the grid. This thin piece seemed to be too thin at high voltages and sparked a great de...
by Jim Kovalchick
Tue May 01, 2018 11:18 am
Forum: Images du Jour
Topic: MATER-1
Replies: 10
Views: 1541

Re: MATER-1

This is an amazing fusor, and I felt privileged to participate in some of the first operations of it. It controls like a dream compared to my own especially after the alumina tube was removed from the stem just approaching the grid. Some improvements like a tungsten grid, a secondary ground grid, an...
by Jim Kovalchick
Tue Feb 20, 2018 6:28 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Saving another PNC-1
Replies: 6
Views: 1764

Re: Saving another PNC-1

I have never seen a schematic or manual. There are a few common issues. 1. Tube failure - To test for tube failure, attach the tube to a different device like a Ludlum 2000 scaler. Adjust the voltage to 1400 to 1600 and use a 1.5 mV threshold. See if you can get some counts. You can also check to se...
by Jim Kovalchick
Tue Feb 13, 2018 10:42 am
Forum: Images du Jour
Topic: Wait, what? Tiny fusors? Not for me!
Replies: 43
Views: 4709

Re: Wait, what? Tiny fusors? Not for me!

Richard, I dont watch pressure much during runs because I don't control by it. I recall around 7 mtorr when I was done. That number is uncorrected for deuterium.
by Jim Kovalchick
Mon Feb 12, 2018 8:25 pm
Forum: Images du Jour
Topic: Wait, what? Tiny fusors? Not for me!
Replies: 43
Views: 4709

Re: Wait, what? Tiny fusors? Not for me!

Tried to break in my new grid today. Still a little noisy nearing 40 kV but starting to settle below that. Neutron numbers are improving with this grid's ability to take current. At 38 kV and 12 mA my BF3 tube was around 700 cpm. My rough estimate is 1.7+ million neutrons/sec.
by Jim Kovalchick
Sat Feb 03, 2018 3:15 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Fusion Claim - Jackson Oswalt
Replies: 15
Views: 2300

Re: Fusion Claim - Jackson Oswalt

Congrats Jackson!

You have a fine system. What are your plans for it? I recommend some activation. With a small fusor you can get in close with your samples. Silver is an easy starter.
by Jim Kovalchick
Mon Jan 29, 2018 12:15 pm
Forum: Images du Jour
Topic: Wait, what? Tiny fusors? Not for me!
Replies: 43
Views: 4709

Re: Wait, what? Tiny fusors? Not for me!

A few more notes on the grid construction techniques I am using: 1. I wasn't sure at first how I was going to cut the braided tungsten. I have a hard enough time getting good cuts on single strand tungsten. You can't use cheap wire cutters because it will chunk your cutting edge. To my pleasure, I w...
by Jim Kovalchick
Mon Jan 29, 2018 12:01 am
Forum: Images du Jour
Topic: Wait, what? Tiny fusors? Not for me!
Replies: 43
Views: 4709

Re: Wait, what? Tiny fusors? Not for me!

My current grid gets a little thermionically unstable at the high end of my operating range. I would like a little more current and voltage so I am pondering a new grid. I haven't installed it yet, but this one uses heavy braided tungsten instead of single strand. This also only has two loops becaus...
by Jim Kovalchick
Sun Jan 21, 2018 12:22 am
Forum: Images du Jour
Topic: Wait, what? Tiny fusors? Not for me!
Replies: 43
Views: 4709

Re: Wait, what? Tiny fusors? Not for me!

I was able to fix my variable leak valve. Turns out that if the screw drive is slightly misaligned it can momentarily reverse act. A simple adjustment fixed the issue. Now that I have smoother gas control to walk up my voltage I toyed with some longer 40 kV operation. Tonight I sandwiched a one ounc...
by Jim Kovalchick
Fri Jan 19, 2018 6:37 pm
Forum: Fusor and/or General Fusion Theory (& FAQs)
Topic: Neutron temperature
Replies: 5
Views: 809

Re: Neutron temperature

The reason it gets referred to so often for neutrons versus anything else is because reaction cross sections vary significantly for neutron especially when comparing fast to thermalized. Neutron cross sections have been hugely important going back the Manhattan Project and then reactor design. The s...